714 Journal of the Department op Agriculture. 



heap. In the Middelburg District, tlie committee was assured by 

 farmers who gave evidence at Eooikraal, the value of returnino- the 

 straw to the soil is realized, and it is so applied, either directly or 

 indirectly through the kraals. 



The committee, dealing in its report (pars. 28 and 24) with the 

 grain lands of the south-western region, pointed out that the out- 

 stniuling deficiency of these soils is humus or decayed organic matter, 

 Avliich hi valued as nrj(,'li for its quality of keejjing soils in good 

 physical condition as for its chemical constituents and proi)erties. 

 The report proceeds to advise that no economical means of supplying 

 humus to those soils sliould he omitted, and states that a very ready 

 and cheap method of assisting in tliis object is that of returning the 

 straw to the land after the giain lias been thrashed, either as suf;h, 

 or through the kraals or stables. The straw, it is pointed out, is a 

 valuable by-product, of which the fullest use should be made, instead 

 of its being left to waste on the farms, or being burned as undesirable 

 material, a proceeding which the committee, in its report, characterizes 

 as " a thoughtless process of soil-exliaustion, which leaves the farmer in 

 deeper debt each year to his soils." Knowing what we do of micro- 

 scopic ferments, we can the more readily understand how the organic 

 matter of straw, that is to say the part which can be burnt off, is 

 useful in forming food for the micro-organisms that help the crops 

 by causing fermentation and decay. 



The report mentions three important directions in which the 

 addition of organic matter would improve the grain soils of the south- 

 western distiicts; it would give them body; it would improve their 

 physical texture; it would render them more absorptive and retentive 

 of moisture without being wet or boggy : a soil which contains much 

 organic matter is very porous and possesses considerable capillary 

 power. But the addition of organic matter would do more than this. 

 " The chief value of straw considered as a fertilizer," says Storer, 

 " must be attributed to the ash ingredients which are contained in it." 

 The grain farmers were rightly told, over and over again, during their 

 meetings with the committee, that the two main needs in making up 

 wheat-fertilizers are nitrogen and phosphates. During its growth a 

 wheat crop takes large quantities of nitrogen and phosphoric oxide 

 and a smaller proportion of potash out of the soil, but a wheat crop 

 can no more come to perfection without potash than it can without 

 nitrogen or phosphates. When straw is burned, the potash, lime, and 

 phosphoric oxide wdiich it contains are left behind in ash, bul even 

 when straw is not burned but applied to the land either direct or 

 through the kraals, all the ash-ingredients remain in it and so get 

 back into the soil. If the straw is returned to the land every season 

 the farmer thus uses these ash-ingredients over and over again, and 

 is saved the necessity of purchasing artificial fertilizers which he 

 would have to do in large quantities if he does not wish his ancestral 

 source of income, as the Departmental Committee phrased it in its 

 report, to present an overdrawn account for immediate attention ; 

 in other words, if he does not want his soil to become utterly 

 exhausted; the committee, in no uncertain terms, warned the farmers 

 ia the country's most extensive wheat areas of " the natural infer- 

 tility of the soils and their steady impoverishment under the present 

 cereal-cropping system," 



Professor F. H. Storer, in his work on " Agriculture in some of 



